A variety of kites are presently commercially available for recreational purposes, or for use by the serious competitor aiming to excel at competition kite-sailing. Depending on the design of a particular kite and the materials used to construct it, it may be flown in light or moderate winds and maneuvered to exhibit aerial feats of different degrees of difficulty.
Kites generally fall into two broad categories: those that are flown with a single string and those flown with two strings affixed to the kite. A variety of single-string kites are well-known, including the Chinese kite, barrel kite, Malay kite, Marconi-jib kite, and Indian-fighter kite. While there are significant differences in the wind speed single-string kites can be flown at, as well as the type of maneuvers each can perform, it is generally true that they perform best in low to moderate winds and are incapable of exhibiting radical aerial maneuvers such as direct overhead flight and dramatic turns accompanied by nearly parallel flight to the ground. Because of the limited weather conditions and limited maneuverability in which single-string kites can be flown, two-string kites that exhibit a wide range of desirable properties have been accepted among kite enthusiasts.
As is apparent from the name, a primary feature of two-string kites is the attachment of two strings of equal length to the kite, one to the right and left sides of the kite, respectively. By pulling on either of the strings, the kite enthusiast can put a two-string kite through exceptional maneuvers. Indeed, the maneuverability of two-string kites is due to constant adjustment of the tension on the string. When tension is applied to either the right or left string, the kite responds by moving in the corresponding direction. If tension is continuously applied evenly on one string, the kite turns continuously in that direction. For example, a clockwise spin is imparted to the kite by pulling in on the right string and stopped by sequentially pulling in on the left string. By exerting even tension on both lines after a particular line of flight is established, the direction of flight can be conserved. Thus, a variety of aerial maneuvers can be performed by sequentially pulling on either the right or left strings.
A feature that distinguishes single-string from dual-string kites is the flight angle of attack. Single-string kites fly at a near fixed angle of attack to the ground, whereas dual-string kites exhibit a variable angle of attack. When the angle of attack is great, a dual-string kite is capable of obtaining high speeds and performing rapid turns. The maximum angle of attack occurs when the kite is nearly parallel to the ground and the wind is at the back of the person controlling the strings.
Several dual-string kites are presently commercially available with names that adequately describe their raucous aerial maneuverability, such as Sky Cat, Sky-Ro-Gyro, and Super Stuntor. Regardless of the type of kite, however, they all share several undesirable features that limit the conditions under which they can be flown or the types of maneuvers that they are capable of performing, even in the hands of an experienced kite flier. First, all the kites require that they be launched by hand, or, alternatively, that the flier be highly experienced to launch it alone. Thus, most of the two-string kites necessarily require that two people be present initially to fly the kite, one to launch it and another to control the strings. Second, most two-string kites presently available can not be flown efficaciously in variable wind speeds of between 10-25 miles per hour without adjusting the point of attachment of the string s to the kite. In kite flying competition, it is highly advantageous to have a kite that can perform different maneuvers without having to make such adjustments so as to avoid grounding the kite and losing competition time needed to make the necessary changes.
Third, most two-string kites cannot readily perform direct overhead 360-degree turns. Last, two-string kites are, for the most part, limited to being flown in winds of up to 25 miles per hour and not higher.